Utilizing word problems relevant to the data processing field, this workbook presents a concept-oriented approach to competency development in ten areas of basic mathematics: (1) the expression of numbers as figures and words; (2) the multiplication, addition, and division of whole numbers, fractions, and decimals; (3) ratios and proportions; (4) percents; (5) number systems; (6) measurement; (7) introductory algebra; (8) problem-solving; (9) statistics; and (10) illustrative aids such as graphs, charts, and tables. For each competency area, the workbook presents a series of word problems designed to reinforce student learning and to demonstrate the applicability of the concept to the data processing work environment. An answer key for the exercises is appended. (JP)